NPORT-P false 0001107414 XXXXXXXX S000050331 C000158901 C000158903 C000158902 STATE STREET INSTITUTIONAL INVESTMENT TRUST 811-09819 0001107414 549300P1E098W6ES7M39 One Iron Street Boston 02210 617-664-7037 STATE STREET SMALL/MID CAP EQUITY INDEX FUND S000050331 54930090OO78X0U66F30 2025-12-31 2025-03-31 N 593664335.70 49930.47 593614405.23 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 N State Street Small/Mid Cap Equity Index Portfolio 54930001FXUIVS800B48 85749T707 2060189.95000000 NS USD 593664335.70000000 100.0084112631 Long EC RF US N 1 N N N 2025-04-29 STATE STREET INSTITUTIONAL INVESTMENT TRUST Arthur Jensen Arthur Jensen Deputy Treasurer XXXX